1. Field of the Invention
The present invention relates to an automated actuation device for releasing items within a confined space. In particular, the present invention relates to an automated pickup head and gripping plate assembly which is used to grip egg cartons or trays and place those egg cartons or trays in stacks in a shipping container or basket.
2. Description of the Art
Eggs are often packaged and sold in rectangular cartons containing a dozen or a dozen-and-a-half eggs (e.g., two or three rows of six eggs), which egg cartons are manufactured of a lightweight material such as polystyrene or cardboard. Eggs are also often shipped or processed using a generally square egg tray containing two-and-a-half dozen eggs (e.g., five rows of six eggs), which egg trays are generally manufactured of a pulp material or plastic. During a process of grading eggs at an egg farm or an egg processing plant, eggs are generally segregated according to, inter alia, size and condition, and are thereafter packed into the above-described egg cartons or trays. Usually, the egg cartons or trays are then stacked within larger shipping containers or wire plastic baskets for later transportation to a retail outlet. Because eggs are a fragile commodity, and because the egg cartons or trays into which eggs are shipped or processed are not particularly strong, it is necessary for the egg cartons or trays stacked in a shipping container or basket to be fairly tightly packed. Tight packing of egg cartons or trays in a shipping container or basket ensures minimum movement of the eggs and egg cartons or trays within the shipping container or basket, thereby reducing the chance of egg breakage during transportation.
Tight packing of egg cartons or trays within a shipping container or basket is generally accomplished using a shipping container or basket having very little clearance between the inside walls of the shipping container or basket and the outside edges of egg cartons or trays stacked therein. This small clearance can make gentle packing of egg cartons or trays, particularly those egg cartons or trays in the bottom of the shipping container or basket, difficult. Careful hand packing of the shipping containers or baskets can ensure gentle packing of egg cartons or trays within a shipping container or basket. However, hand packing of shipping containers or baskets reduces the speed at which the shipping containers or baskets may be packed, increases labor costs, and can result in repetitive motion injuries to the individuals doing the packing. It is therefore desirable to automate the process of packing shipping containers or baskets with egg cartons or trays. The limited clearance between the outside edges of egg cartons or trays being packed and the inside walls of the shipping container or basket severely limits the amount of space available for an automatic packing device to operate, presenting limitations on the design and operation of any automated packing apparatus. In particular, the limited clearance confines the dimensions of the packing device, which must be capable of being inserted within the interior of the shipping container or basket so as to prevent the need to drop cartons or trays into the bottom of the shipping container or basket. Furthermore, the limited clearance also confines the movement of the gripping structure on the packing device because the gripping structure must open to release the egg cartons or trays in the limited clearance between the outside edges of the egg cartons or trays and the inside walls of the shipping container or basket.